With all flowmeters in which electrodes are required to make electrical contact with a fluid in the flowmeter, there exists a problem of ensuring that the contact resistance between the electrodes and the fluid is uniform. Variation in contact resistance can be caused by deposition of solid matter suspended in the fluid, by the appearance of gas bubbles and by chemical action. It has been found that this problem can largely be avoided by using electrodes which are small enough to be regarded as points. However, flowmeters having point electrodes suffer from the disadvantage that they are over-sensitive to flow near the electrodes so that the calibration of the flowmeter is seriously affected by variations in the velocity profile of fluids flowing therethrough. The present invention is concerned with the provision of an electromagnetic flowmeter having a magnetic field which varies in such a manner as to reduce this disadvantage.